Composition for dyeing keratin fibers with a cationic direct dye and a thickening polymer

ABSTRACT

The invention relates to a composition for dyeing keratin fibers, in particular human keratin fibers such as the hair, comprising at least one cationic direct dye of given formula and at least one thickening polymer chosen from nonionic guar gums, biopolysaccharide gums of microbial origin, gums derived from plant exudates, pectins, alginates, starches, and carboxyalkylcelluloses. The invention also relates to the dyeing processes and dyeing devices using the composition.

[0001] The invention relates to a composition for dyeing keratin fibers,in particular human keratin fibers such as the hair, comprising, in amedium which is suitable for dyeing, at least one cationic direct dye ofgiven formula and at least one specific thickening polymer. Theinvention also relates to the dyeing processes and dyeing devices, i.e.,kits, using the composition.

[0002] Two types of dyeing may be distinguished in the haircare sector.The first is semi-permanent or temporary dyeing, or direct dyeing, whichuses dyes capable of giving the hair a natural coloration, a more orless pronounced color change which may withstand shampooing severaltimes. These dyes are also known as direct dyes; they can be used withor without an oxidizing agent. In the presence of an oxidizing agent,the aim is to obtain lightening dyeing. Lightening dyeing is carried outby applying a mixture, prepared at the time of use, of a direct dye andan oxidizing agent to the hair, and makes it possible in particular toobtain, by lightening the melanin in the hair, an advantageous effectsuch as a unified color in the case of grey hair, or to bring out thecolor in the case of naturally pigmented hair.

[0003] The second is permanent dyeing or oxidation dyeing. This iscarried out with so-called “oxidation” dyes comprising oxidation dyeprecursors and couplers. Oxidation dye precursors, commonly known as“oxidation bases”, are compounds which are initially colorless or weaklycolored which develop their dyeing power on the hair in the presence ofoxidizing agents added at the time of use, leading to the formation ofcolored compounds and dyes. The formation of these colored compounds anddyes results either from an oxidative condensation of the “oxidationbases” with themselves or from an oxidative condensation of theoxidation bases with coloration-modifying compounds commonly known as“couplers”, which are generally present in the dye compositions used inoxidation dyeing.

[0004] It is known practice to add direct dyes to oxidation dyes inorder to vary the shades obtained with the said oxidation dyes or toenrich the shades with glints. Among the cationic direct dyes availablein the sector of dyeing keratin fibers, in particular human keratinfibers, the compounds whose structure is developed in the texthereinbelow are already known; nevertheless, these dyes lead tocolorations which have characteristics that could still be improved,such as the intensity, the homogeneity of the color distributed alongthe fiber, in which case the coloration is said to be too selective, andthe staying power, in terms of the resistance to the various attackingfactors to which the hair may be subjected (light, bad weather,shampooing).

[0005] After considerable research conducted in this matter, the presentinventors have discovered that it is possible to obtain novelcompositions for dyeing keratin fibers which are capable of giving moreintense and yet unselective colorations which show good resistance tothe various attacking factors to which the hair may be subjected, bycombining at least one specific thickening polymer with at least oneknown cationic direct dye of the prior art, which have the respectiveformulae defined below. This discovery forms the basis of the presentinvention.

[0006] A first subject of the present invention is thus a compositionfor dyeing keratin fibers, and in particular human keratin fibers suchas the hair, containing, in a medium which is suitable for dyeing, (i)at least one cationic direct dye whose structure corresponds to formulae(I) defined below, characterized in that it also contains (ii) at leastone specific thickening polymer.

[0007] (i) The cationic direct dye which can be used according to thepresent invention is a compound of formula (I) below:

A—N═N—B  (I)

[0008] in which:

[0009] the symbol A represents a group chosen from the structures A₁ toA₃ below:

[0010]  in which structures A₁ to A₃,

[0011] R₁ denotes a C₁-C₄ alkyl radical, a phenyl radical which can besubstituted with a C₁-C₄ alkyl radical or a halogen atom chosen fromchlorine, bromine, iodine and fluorine;

[0012] R₂ denotes a C₁-C₄ alkyl radical or a phenyl radical;

[0013] R₃ and R₄, which may be identical or different, represent a C₁-C₄alkyl radical, a phenyl radical or else, in the case of structure A1,can together form a benzene ring substituted with one or more C₁-C₄alkyl, C₁-C₄ alkoxy or NO₂ radicals and, in the case of structure A2,can together form a benzene ring optionally substituted with one or moreC₁-C₄ alkyl, C₁-C₄ alkoxy or NO₂ radicals;

[0014] R₃ can also denote a hydrogen atom;

[0015] Z denotes an oxygen or sulphur atom or a group —NR₂;

[0016] M represents a —CH, —CR (R denoting C₁-C₄ alkyl) or —N⁺R₅(X⁻)_(r) group;

[0017] K represents a —CH, —CR (R denoting C₁-C₄ alkyl) or —N⁺R₅(X⁻)_(r) group;

[0018] P represents a —CH, —CR (R denoting C₁-C₄ alkyl) or —N⁺R₅(X⁻)_(r) group; r denotes zero or 1;

[0019] R₅ represents an atom O⁻, a C₁-C₄ alkoxy radical or a C₁-C₄ alkylradical;

[0020] R₆ and R₇, which may be identical or different, represent ahydrogen atom, a halogen atom chosen from chlorine, bromine, iodine andfluorine, a C₁-C₄ alkyl or C₁-C₄ alkoxy radical or an —NO₂ radical;

[0021] X⁻ represents an anion preferably chosen from chloride, iodide,methyl sulphate, ethyl sulphate, acetate and perchlorate;

[0022]  with the proviso that,

[0023] if R₄ denotes a C₁-C₄ alkyl radical and Z denotes a sulphur atom,R₃ does not denote a hydrogen atom; if R₅ denotes O⁻, then r denoteszero;

[0024] if K or P or M denote C₁-C₄—N⁺-alkyl X⁻, then R₆ or R₇ is otherthan a hydrogen atom;

[0025] if K denotes —N⁺ R₅(X⁻)_(r), then M═P═—CH, —CR;

[0026] if M denotes —N⁺ R₅(X⁻)_(r), then K═P═—CH, —CR;

[0027] if P denotes —N⁺ R₅(X⁻)_(r), then K═M and denote —CH or —CR;

[0028] if Z denotes —NR₂ and R₂ denotes a C₁-C₄ alkyl radical, then atleast one of the radicals R₁, R₃ or R₄ of the group of structure A₂ isother than a C₁-C₄ alkyl radical;

[0029] the symbol B represents:

[0030] (a) a group of structure B₁ below:

[0031]  in which structure B₁,

[0032] R₈ represents a hydrogen atom, a halogen atom chosen fromchlorine, bromine, iodine and fluorine, a C₁-C₄ alkyl or C₁-C₄ alkoxyradical, a radical —OH, —NO₂, —NHR₁₁, —NR₁₂R₁₃, —NHCO (C₁-C₄) alkyl, orforms with R₉ a 5- or 6-membered ring which may or may not contain oneor more hetero atoms chosen from nitrogen, oxygen and sulphur;

[0033] R₉ represents a hydrogen atom, a halogen atom chosen fromchlorine, bromine, iodine and fluorine, a C₁-C₄ alkyl or C₁-C₄ alkoxyradical or forms, with R₁₀ or R₁₁, a 5- or 6-membered ring which may ormay not contain one or more hetero atoms chosen from nitrogen, oxygenand sulphur;

[0034] R₁₀ represents a hydrogen atom, an —OH radical, a radical —NHR₁₁or a radical —NR₁₂R₁₃;

[0035] R₁₁ represents a hydrogen atom, a C₁-C₄ alkyl radical, a C₁-C₄monohydroxyalkyl radical, a C₂-C₄ polyhydroxyalkyl radical or a phenylradical;

[0036] R₁₂ and R₁₃, which may be identical or different, represent aC₁-C₄ alkyl radical, a C₁-C₄ monohydroxyalkyl radical or a C₂-C₄polyhydroxyalkyl radical;

[0037] (b) a 5- or 6-membered nitrogenous heterocyclic group which cancontain other hetero atoms and/or carbonyl groups and which can besubstituted with one or more C₁-C₄ alkyl, amino or phenyl radicals, andin particular a group of structure B₂ below:

[0038]  in which structure B₂,

[0039] R₁₄ and R₁₅, which may be identical or different, represent ahydrogen atom, a C₁-C₄ alkyl radical or a phenyl radical;

[0040] Y denotes the —CO— radical or the radical

[0041] n=0 or 1, with, when n denotes 1, U denoting a —CO— radical.

[0042] In the structures defined above, the C₁-C₄ alkyl or alkoxy grouppreferably denotes methyl, ethyl, butyl, methoxy or ethoxy.

[0043] The cationic direct dyes of formula (I) which can be used in thedye compositions in accordance with the invention are known compoundsand are described, for example, in patent applications FR-2,189,006,FR-2,285,851 and FR-2,140,205 and its Certificates of Addition, thedisclosure of each of which is specifically incorporated by referenceherein.

[0044] Among the cationic direct dyes of formula (I) which can be usedin the dye compositions in accordance with the invention, mention may bemade more particularly of the compounds of structures (I)₁ to (I)₇₇below:

[0045] The cationic direct dye(s) of formula (I) used according to theinvention preferably represent(s) from 0.001 to 10% by weightapproximately relative to the total weight of the dye composition andeven more preferably from 0.005 to 5% by weight approximately relativeto this weight.

[0046] (ii) The thickening polymer which can be used according to thepresent invention is a polysaccharide or a cellulose chosen from:

[0047] (ii)₁—nonionic guar gums;

[0048] (ii)₂—biopolysaccharide gums of microbial origin, such asscleroglucan gum or xanthan gum;

[0049] (ii)₃—gums derived from plant exudates, such as gum arabic,ghatti gum, karaya gum, gum tragacanth, carrageenan gum, agar gum andcarob gum;

[0050] (ii)₄—pectins;

[0051] (ii)₅—alginates;

[0052] (ii)₆—starches;

[0053] (ii)₇—carboxyalkylcelluloses.

[0054] The nonionic guargums can be modified or unmodified. Theunmodified guar gums are, for example, the products sold under the nameVidogum GH 175 by the company Unipectine and under the name Jaguar C bythe company Meyhall.

[0055] According to the present invention, it is preferred to usenonionic guar gums modified with C₁-C₆ hydroxyalkyl groups.

[0056] Among the hydroxyalkyl groups which may be mentioned, forexample, are hydroxymethyl, hydroxyethyl, hydroxypropyl and hydroxybutylgroups. These guar gums are well known in the state of the art and canbe prepared, for example, by reacting the corresponding alkene oxidessuch as, for example, propylene oxides, with guar gum so as to obtain aguar gum modified with hydroxypropyl groups. The degree ofhydroxyalkylation, which corresponds to the number of alkylene oxidemolecules consumed by the number of free hydroxyl functions present onthe guar gum, preferably ranges from 0.4 to 1.2.

[0057] Such nonionic guar gums optionally modified with hydroxyalkylgroups are sold, for example, under the trade names Jaguar HP8, JaguarHP60 and Jaguar HP120, Jaguar DC 293 and Jaguar HP 105 by the companyRhône-Poulenc (Meyhall) or under the name Galactasol 4H4FD2 by thecompany Aqualon.

[0058] The biopolysaccharide gums of microbial origin, such asscleroglucan gum or xanthan gum, the gums derived from plant exudatessuch as gum arabic, ghatti gum, karaya gum, gum tragacanth, carrageenangum, agar gum and carob gum, the hydroxyalkylcelluloses andcarboxymethylcelluloses, pectins, alginates and starches are well knownto those skilled in the art and are described in particular in the bookby Robert L. Davidson entitled “Handbook of Water soluble gums andresins” published by McGraw Hill Book Company (1980), the disclosure ofwhich is specifically incorporated by reference herein.

[0059] Among these gums, the scleroglucans more particularly usedaccording to the present invention are represented by the products soldunder the name Actigum CS by the company Sanofi Bio Industries and inparticular Actigum CS 11, and under the name Amigel by the company AlbanMuller International. Other scleroglucans, such as the one treated withglyoxal in French patent application No. 2,633,940, the disclosure ofwhich is specifically incorporated by reference herein, can also beused.

[0060] The xanthan gums more particularly used according to the presentinvention are represented by the products sold under the names Keltrol,Keltrol T, Keltrol TF, Keltrol BT, Keltrol RD and Keltrol CG by thecompany Nutrasweet Kelco, or under the names Rhodicare S and Rhodicare Hby the company Rhodia Chimie.

[0061] Among the carboxyalkylcelluloses preferably used iscarboxymethylcellulose, for which mention may be made of the productssold under the names Blanose 7M8/SF, Blanose Raffinée 7M, Blanose 7LF,Blanose 7MF, Blanose 9M31F, Blanose 12M31XP, Blanose 12M31P, Blanose9M31XF, Blanose 7H, Blanose 7M31 and Blanose 7H3SXF by the companyAqualon, or Aquasorb A500 and Ambergum 1221 by the company Hercules, orCellogen HP810A and Cellogen HP6HS9 by the company Montello, orPrimellose by the company Avebe.

[0062] The thickening polymers (ii) used in the compositions of thepresent invention are preferably present in a proportion of from 0.01 to10% by weight approximately, in particular in a proportion of from 0.1to 5% by weight approximately, relative to the total weight of the dyecomposition applied to the keratin fibers.

[0063] The medium which is suitable for dyeing (or support) generallycomprises water or a mixture of water and at least one organic solventto dissolve the compounds which would not be sufficiently water-soluble.As organic solvents, mention may be made, for example, of C₁-C₄ loweralkanols such as ethanol and isopropanol; aromatic alcohols such asbenzyl alcohol, as well as similar products and mixtures thereof.

[0064] The solvents can be present in proportions preferably rangingfrom 1 to 40% by weight approximately relative to the total weight ofthe dye composition, and even more preferably from 5 to 30% by weightapproximately.

[0065] The pH of the dye composition in accordance with the invention isgenerally approximately ranging from 2 to 11 and preferablyapproximately ranging from 5 to 10. It can be adjusted to the desiredvalue using acidifying or basifying agents usually used for dyeingkeratin fibers.

[0066] Among the acidifying agents, mention may be made, by way ofexample, of inorganic or organic acids such as hydrochloric acid,orthophosphoric acid, sulphuric acid, carboxylic acids such as aceticacid, tartaric acid, citric acid and lactic acid, and sulphonic acids.

[0067] Among the basifying agents, mention may be made, by way ofexample, of aqueous ammonia, alkaline carbonates, alkanolamines such asmono-, di- and triethanolamine and derivatives thereof, sodiumhydroxide, potassium hydroxide and the compounds of formula (II) below:

[0068] in which W is a propylene residue optionally substituted with ahydroxyl group or a C₁-C₆ alkyl radical; R₁₆, R₁₇, R₁₈ and R₁₉, whichmay be identical or different, represent a hydrogen atom or a C₁-C₆alkyl or C₁-C₆ hydroxyalkyl radical.

[0069] In addition to the cationic direct dye(s) (i) defined above, thedye composition in accordance with the invention can contain one or moreadditional direct dyes which can be chosen, for example, fromnitrobenzene dyes, anthraquinone dyes, naphthoquinone dyes,triarylmethane dyes, xanthene dyes and azo dyes which are non-cationic.

[0070] When it is intended for oxidation dyeing, the dye composition inaccordance with the invention contains, in addition to the cationicdirect dye(s) (i), one or more oxidation bases chosen from the oxidationbases conventionally used for oxidation dyeing and among which mentionmay be made in particular of para-phenylenediamines,bis(phenyl)alkylenediamines, para-aminophenols, ortho-aminophenols andheterocyclic bases.

[0071] When they are used, the oxidation base(s) preferably represent(s)from 0.0005 to 12% by weight approximately relative to the total weightof the dye composition, and even more preferably from 0.005 to 6% byweight approximately relative to this weight.

[0072] When it is intended for oxidation dyeing, the dye composition inaccordance with the invention can also contain, in addition to thecationic direct dye (i) and the thickening polymer (ii) as well as theoxidation bases, one or more couplers so as to modify the shadesobtained or to enrich them with glints, by using the cationic directdye(s) (i) and the oxidation base(s).

[0073] The couplers which can be used in the dye composition inaccordance with the invention can be chosen from the couplers usedconventionally in oxidation dyeing and among which mention may be madein particular of meta-phenylenediamines, meta-aminophenols,meta-diphenols and heterocyclic couplers.

[0074] When it is (they are) present, the coupler(s) preferablyrepresent(s) from 0.0001 to 10% by weight approximately relative to thetotal weight of the dye composition, and even more preferably from 0.005to 5% by weight approximately relative to this weight.

[0075] The dye composition in accordance with the invention can alsocontain various adjuvants conventionally used in compositions for dyeingthe hair, such as antioxidants, penetrating agents, sequestering agents,fragrances, buffers, dispersing agents, surfactants, film-formingagents, ceramides, preserving agents, screening agents, such assunscreens, and opacifiers.

[0076] Needless to say, a person skilled in the art will take care toselect this (these) optional complementary compound(s) such that theadvantageous properties intrinsically associated with the dyecomposition in accordance with the invention are not, or are notsubstantially, adversely affected by the addition(s) envisaged.

[0077] The dye composition according to the invention can be in variousforms, such as in the form of liquids, shampoos, creams or gels or anyother form which is suitable for dyeing keratin fibers, and inparticular human hair. It can be obtained by mixing, at the time of use,a composition, which may be pulverulent, containing the cationic directdye(s) with a composition containing the specific thickening polymer.

[0078] When the combination of the cationic direct dye (i) and thethickening polymer (ii) according to the invention is used in acomposition intended for oxidation dyeing (in which case one or moreoxidation bases are used, optionally in the presence of one or morecouplers) or when it is used in a composition intended for lighteningdirect dyeing, then the dye composition in accordance with the inventionalso comprises at least one oxidizing agent chosen, for example, fromhydrogen peroxide, urea peroxide, alkali metal bromates, persalts suchas perborates and persulphates, and enzymes such as peroxidases,lactases and two-electron oxidoreductases. It is particularly preferredto use hydrogen peroxide or enzymes.

[0079] Another subject of the invention is a process for dyeing keratinfibers, and in particular human keratin fibers such as the hair, usingthe dye composition as defined above.

[0080] According to a first variant of this dyeing process in accordancewith the invention, at least one dye composition as defined above isapplied to the fibers, for a period which is sufficient to develop thedesired coloration, after which the fibers are rinsed, optionally washedwith shampoo, rinsed again and dried.

[0081] The time required to develop the coloration on the keratin fibersis generally from 3 to 60 minutes and even more specifically from 5 to40 minutes.

[0082] According to a second variant of this dyeing process inaccordance with the invention, at least one dye composition as definedabove is applied to the fibers, for a period which is sufficient todevelop the desired coloration, without final rinsing.

[0083] According to one specific embodiment of this dyeing process, andwhen the dye composition in accordance with the invention comprises atleast one oxidation base and at least one oxidizing agent, the dyeingprocess comprises a first step which comprises separately storing, onthe one hand, a composition (A1) comprising, in a medium which issuitable for dyeing, at least one cationic direct dye (i) as definedabove and at least one oxidation base, and, on the other hand, acomposition (B1) comprising, in a medium which is suitable for dyeing,at least one oxidizing agent, and then in mixing them together at thetime of use, after which this mixture is applied to the keratin fibers,the composition (A1) or the composition (B1) containing the thickeningpolymer (ii) as defined above.

[0084] According to another specific embodiment of this dyeing process,and when the dye composition in accordance with the invention comprisesat least one oxidizing agent, the dyeing process comprises a first stepwhich comprises separately storing, on the one hand, a composition (A2)comprising, in a medium which is suitable for dyeing, at least onecationic direct dye (i) as defined above, and, on the other hand, acomposition (B2) comprising, in a medium which is suitable for dyeing,at least one oxidizing agent, and then in mixing them together at thetime of use, after which this mixture is applied to the keratin fibers,the composition (A2) or the composition (B2) containing the thickeningpolymer as defined above.

[0085] Another subject of the invention is a multi-compartment dyeingdevice, i.e., a dyeing “kit” or any other multi-compartment packagingsystem, a first compartment of which comprises the composition (A1) or(A2) as defined above and a second compartment of which comprises thecomposition (B1) or (B2) as defined above. These devices can be equippedwith means for dispensing the desired mixture onto the hair, such as thedevices described in patent FR 2,586,913, the disclosure of which isspecifically incorporated by reference herein.

[0086] The examples which follow are intended to illustrate theinvention without, however, limiting its scope.

EXAMPLES Examples 1 to 2

[0087] The two direct dyeing compositions given in the table below wereprepared: Example Example 1 2 Cationic direct dye of formula (I)10 0.12Cationic direct dye of formula (I)27 0.1 Guar gum sold under the nameVidogum GH 1.0 AM* 175 by the company Unipectine Scleroglucan gum soldunder the name 1.0 AM* Amigel by the company Alban Muller InternationalEthanol 10 10 2-Amino-2-methyl-1-propanol qs pH 9 pH 9 Demineralizedwater qs 100 100

[0088] The above compositions were each applied for 30 minutes to locksof natural grey hair containing 90% white hairs. The locks of hair werethen rinsed, washed with a strandard shampoo and then dried.

[0089] The locks were dyed in the following shades: Examples Shadesobtained 1 Bright red 3 Bright purple

What is claimed is:
 1. A ready-to-use composition for dyeing keratinfibers comprising: (i) at least one cationic dye chosen from compoundsof formula (I) below: A—N═N—B  (I)  in which: the symbol A represents agroup chosen from the structures A₁ to A₃ below:

 in which structures A₁ to A₃, R₁ is chosen from C₁-C₄ alkyl radicals, aphenyl radical which can be substituted with a C₁-C₄ alkyl radical or ahalogen atom chosen from chlorine, bromine, iodine and fluorine; R₂ ischosen from C₁-C₄ alkyl radicals and a phenyl radical; R₃ and R₄, whichmay be identical or different, are chosen from C₁-C₄ alkyl radicals, aphenyl radical or, together form, in A₁, a benzene ring substituted withat least one radical chosen from C₁-C₄ alkyl radicals, C₁-C₄ alkoxyradicals and NO₂ radicals or, together form, in A₂, a benzene ringoptionally substituted with at least one radical chosen from C₁-C₄ alkylradicals, C₁-C₄ alkoxy radicals and NO₂ radicals; R₃ can be furtherchosen from a hydrogen atom; Z is chosen from an oxygen atom, a sulphuratom and —NR₂ radicals; M is chosen from a —CH radical, —C(C₁-C₄ alkyl)radicals and —N⁺ R₅(X⁻)_(r) radicals; K is chosen from a —CH radical,—C(C₁-C₄ alkyl) radicals and —N⁺ R₅(X⁻)_(r) radicals; P is chosen from a—CH radical, —C(C₁-C₄ alkyl) radicals and —N⁺ R₅(X⁻)_(r) radicals;wherein r denotes zero or 1; wherein R₅ is chosen from an O⁻ anion,C₁-C₄ alkoxy radicals and C₁-C₄ alkyl radicals; R₆ and R₇, which may beidentical or different, are chosen from a hydrogen atom, halogen atomschosen from chlorine, bromine, iodine and fluorine, C₁-C₄ alkylradicals, C₁-C₄ alkoxy radicals, and —NO₂ radicals; X⁻ is chosen fromanions;  with the proviso that, wherein if R₄ is a C₁-C₄ alkyl radicaland Z denotes a sulphur atom, R₃ is not a hydrogen atom; wherein if R₅is O⁻, then r is zero; wherein if K or P or M is C₁-C₄ —N⁺ -alkyl X⁻,either R₆ or R₇ is not a hydrogen atom; wherein if K is —N⁺ R₅(X⁻)_(r),M and P are the same and are chosen from a —CH radical and —C(C₁-C₄alkyl) radicals; wherein if M is —N⁺ R₅(X⁻)_(r), K and P are the sameand are chosen from a —CH radical and —C(C₁-C₄ alkyl) radicals; if Pdenotes —N⁺ R₅(X⁻)_(r), K and M are the same and are chosen from a —CHradical and —C(C₁-C₄ alkyl) radicals; if Z is —NR₂ with R₂ being aradical chosen from C₁-C₄ alkyl radicals, at least one of the radicalsR₁, R₃ or R₄ of A₂ is not chosen from C₁-C₄ alkyl radicals; the symbol Bis chosen from: (a) a group of structure B₁ below:

 in which structure B₁, R₈ is chosen from a hydrogen atom, a halogenatom chosen from chlorine, bromine, iodine and fluorine, C₁-C₄ alkylradicals, C₁-C₄ alkoxy radicals, a radical —OH, a radical —NO₂, —NHR₁₁radicals, —NR₁₂R₁₃ radicals, —NHCO (C₁-C₄) alkyl radicals, or forms withR₉ a 5- or 6-membered ring which may or may not contain at least onehetero atom chosen from nitrogen, oxygen and sulphur; R₉ is chosen froma hydrogen atom, a halogen atom chosen from chlorine, bromine, iodineand fluorine, C₁-C₄ alkyl radicals, C₁-C₄ alkoxy radicals, or forms,with R₁₀ or R₁₁, a 5- or 6-membered ring which may or may not contain atleast one hetero atom chosen from nitrogen, oxygen and sulphur; R₁₀ ischosen from a hydrogen atom, an —OH radical, —NHR₁₁ radicals and—NR₁₂R₁₃ radicals; R₁₁ is chosen from a hydrogen atom, C₁-C₄ alkylradicals, C₁-C₄ monohydroxyalkyl radicals, C₂-C₄ polyhydroxyalkylradicals and a phenyl radical; R₁₂ and R₁₃, which may be identical ordifferent, are chosen from C₁-C₄ alkyl radicals, C₁-C₄ monohydroxyalkylradicals and C₂-C₄ polyhydroxyalkyl radicals; (b) 5- and 6-memberednitrogenous heterocyclic groups optionally containing other heteroatomsor carbonyl groups and optionally substituted with at least one radicalchosen from C₁-C₄ alkyl radicals, an amino radical, a phenyl radical,and (ii) at least one thickening polymer chosen from polymerscomprising: (ii)₁—nonionic guar gums; (ii)₂—biopolysaccharide gums ofmicrobial origin; (ii)₃—gums derived from plant exudates; (ii)₄—pectins;(ii)₅—alginates; (ii)₆—starches; and (ii)₇—carboxyalkylcelluloses. 2.The composition according to claim 1, wherein said keratin fibers arehuman keratin fibers.
 3. The composition according to claim 2, whereinsaid human keratin fibers are hair.
 4. The composition according toclaim 1, wherein in formula (I) the symbol B represents a group ofstructure of B₂ below:

in which structure B₂, R₁₄ and R₁₅, which may be identical or different,are chosen from a hydrogen atom, C₁-C₄ alkyl radicals and phenylradicals; Y is chosen from a —CO— radical and a radical

n is 0 or 1, wherein, when n is 1, U is a —CO— radical.
 5. Thecomposition according to claim 1, wherein said anions are chosen fromchloride, iodide, methyl sulphate, ethyl sulphate, acetate andperchlorate.
 6. The composition according to claim 1, wherein in formula(I), the C₁-C₄ alkyl radicals and the C₁-C₄ alkoxy radicals are chosenfrom methyl, ethyl, butyl, methoxy and ethoxy radicals.
 7. Thecomposition according to claim 1, wherein said at least one compound offormula (I) corresponds to the structures (I)₁ to (I)₇₇ below:


8. The composition according to claim 1, wherein said at least onecationic dye of formula (I) is present in an amount ranging from 0.001to 10% by weight relative to the total weight of the composition.
 9. Thecomposition according to claim 8, wherein said at least one cationic dyeof formula (I) is present in an amount ranging from 0.005 to 5% byweight relative to the total weight of the composition.
 10. Thecomposition according to claim 1, wherein said at least one thickeningpolymer is chosen from nonionic guar gums modified with C₁-C₆hydroxyalkyl groups.
 11. The composition according to claim 10, whereinsaid C₁-C₆ hydroxyalkyl groups are chosen from hydroxymethyl,hydroxyethyl, hydroxypropyl and hydroxybutyl groups.
 12. The compositionaccording to claim 1, wherein said biopolysaccharide gums of microbialorigin are chosen from scleroglucan gum and xanthan gum.
 13. Thecomposition according to claim 1, wherein said gums derived from plantexudates are chosen from gum arabic, ghatti gum, karaya gum, gumtragacanth, carrageenan gum, agar gum and carob gum.
 14. The compositionaccording to claim 10, wherein said nonionic guar gums have a degree ofhydroxylation ranging from 0.4 to 1.2.
 15. The composition according toclaim 1, wherein said carboxycelluloses are chosen fromcarboxymethylcelluloses.
 16. The composition according to claim 1,wherein said at least one thickening polymer is present in an amountranging from 0.01 to 10% by weight relative to the total weight of thecomposition.
 17. The composition according to claim 16, wherein said atleast one thickening polymer is present in an amount ranging from 0.1 to5% by weight relative to the total weight of the composition.
 18. Thecomposition according to claim 1, wherein said composition furthercomprises a support chosen from water and a mixture of water and atleast one organic solvent.
 19. The composition according to claim 1,wherein said composition has a pH from 2 to
 11. 20. The compositionaccording to claim 19, wherein said composition has a pH from 5 to 10.21. The composition according to claim 1, wherein said compositionfurther comprises at least one additional direct dye.
 22. Thecomposition according to claim 21, wherein said at least one additionaldirect dye is chosen from nitrobenzene dyes, anthraquinone dyes,napthaquinone dyes, triarylmethane dyes, xanthene dyes and azo dyes. 23.The composition according to claim 1, wherein said composition furthercomprises at least one oxidation base chosen frompara-phenylenediamines, bis(phenyl)alkylenediamines, para-aminophenols,ortho-aminophenols and heterocyclic bases.
 24. The composition accordingto claim 23, wherein said at least one oxidation base is present in anamount ranging from 0.0005 to 12% by weight relative to the total weightof the dye composition.
 25. The composition according to claim 24,wherein said at least one oxidation base is present in an amount rangingfrom 0.005 to 6% by weight relative to the total weight of the dyecomposition.
 26. The composition according to claim 23, wherein saidcomposition further comprises at least one coupler chosen frommeta-phenylenediamines, meta-aminophenols, meta-diphenols andheterocyclic couplers.
 27. The composition according to claim 26,wherein said at least one coupler is present in an amount ranging from0.0001 to 10% by weight relative to the total weight of the dyecomposition.
 28. The composition according to claim 27, wherein said atleast one coupler represents from 0.005 to 5% by weight relative to thetotal weight of the dye composition.
 29. The composition according toclaim 23, wherein said composition further comprises at least oneoxidizing agent.
 30. The composition according to claim 29, wherein saidat least one oxidizing agent is chosen from hydrogen peroxide, ureaperoxide, alkali metal bromates, persalts and enzymes.
 31. Thecomposition according to claim 30, wherein said persalts are chosen fromperborates and persulphates.
 32. The composition according to claim 30,wherein said enzymes are chosen from peroxidases, lactases, andtwo-electron oxidoreductases.
 33. The composition according to claim 1,wherein said composition is present in an amount sufficient forlightening direct dyeing.
 34. The composition according to claim 1,wherein said composition further comprises at least one oxidizing agent.35. The composition according to claim 1, wherein said composition is ina form chosen from a liquid, a shampoo, a cream, and a gel.
 36. Aprocess for dyeing keratin fibers, comprising applying a composition forthe oxidation dyeing of keratin fibers to said keratin fibers anddeveloping for a period of time sufficient to achieve the desiredcoloration, wherein said composition comprises: i) at least one cationicdye chosen from compounds of formula (I) below: A—N═N—B  (I)  in which:the symbol A represents a group chosen from the structures A₁ to A₃below:

 in which structures A₁ to A₃, R₁ is chosen from C₁-C₄ alkyl radicals, aphenyl radical which can be substituted with a C₁-C₄ alkyl radical or ahalogen atom chosen from chlorine, bromine, iodine and fluorine; R₂ ischosen from C₁-C₄ alkyl radicals and a phenyl radical; R₃ and R₄, whichmay be identical or different, are chosen from C₁-C₄ alkyl radicals, aphenyl radical or, together form, in A₁, a benzene ring substituted withat least one radical chosen from C₁-C₄ alkyl radicals, C₁-C₄ alkoxyradicals and NO₂ radicals or, together form, in A₂, a benzene ringoptionally substituted with at least one radical chosen from C₁-C₄ alkylradicals, C₁-C₄ alkoxy radicals and NO₂ radicals; R₃ can be furtherchosen from a hydrogen atom; Z is chosen from an oxygen atom, a sulphuratom and —NR₂ radicals; M is chosen from a —CH radical, —C(C₁-C₄ alkyl)radicals and —N⁺ R₅(X⁻)_(r) radicals; K is chosen from a —CH radical,—C(C₁-C₄ alkyl) radicals and —N⁺ R₅(X⁻)_(r) radicals; P is chosen from a—CH radical, —C(C₁-C₄ alkyl) radicals and —N⁺ R₅(X⁻)_(r) radicals;wherein r denotes zero or 1; wherein R₅ is chosen from an O⁻ anion,C₁-C₄ alkoxy radicals and C₁-C₄ alkyl radicals; R₆ and R₇, which may beidentical or different, are chosen from a hydrogen atom, halogen atomschosen from chlorine, bromine, iodine and fluorine, C₁-C₄ alkylradicals, C₁-C₄ alkoxy radicals, and —NO₂ radicals; X⁻ is chosen fromanions;  with the proviso that, wherein if R₄ is a C₁-C₄ alkyl radicaland Z denotes a sulphur atom, R₃ is not a hydrogen atom; wherein if R₅is O⁻, then r is zero; wherein if K or P or M is C₁-C₄—N⁺ -alkyl X⁻,either R₆ or R₇ is not a hydrogen atom; wherein if K is —N⁺ R₅(X⁻)_(r),M and P are the same and are chosen from a —CH radical and —C(C₁-C₄alkyl) radicals; wherein if M is —N⁺ R₅(X⁻)_(r), K and P are the sameand are chosen from a —CH radical and —C(C₁-C₄ alkyl) radicals; if Pdenotes —N⁺ R₅(X⁻)_(r), K and M are the same and are chosen from a —CHradical and —C(C₁-C₄ alkyl) radicals; if Z is —NR₂ with R₂ being aradical chosen from C₁-C₄ alkyl radicals, at least one of the radicalsR₁, R₃ or R₄ of A₂ is not chosen from C₁-C₄ alkyl radicals; the symbol Bis chosen from: (a) a group of structure B₁ below:

 in which structure B₁, R₈ is chosen from a hydrogen atom, a halogenatom chosen from chlorine, bromine, iodine and fluorine, C₁-C₄ alkylradicals, C₁-C₄ alkoxy radicals, a radical —OH, a radical —NO₂, —NHR₁₁radicals, —NR₁₂R₁₃ radicals, —NHCO (C₁-C₄) alkyl radicals, or forms withR₉ a 5- or 6-membered ring which may or may not contain at least onehetero atom chosen from nitrogen, oxygen and sulphur; R₉ is chosen froma hydrogen atom, a halogen atom chosen from chlorine, bromine, iodineand fluorine, C₁-C₄ alkyl radicals, C₁-C₄ alkoxy radicals, or forms,with R₁₀ or R₁₁, a 5- or 6-membered ring which may or may not contain atleast one hetero atom chosen from nitrogen, oxygen and sulphur; R₁₀ ischosen from a hydrogen atom, an —OH radical, —NHR₁₁ radicals and—NR₁₂R₁₃ radicals; R₁₁ is chosen from a hydrogen atom, C₁-C₄ alkylradicals, C₁-C₄ monohydroxyalkyl radicals, C₂-C₄ polyhydroxyalkylradicals and a phenyl radical; R₁₂ and R₁₃, which may be identical ordifferent, is chosen from C₁-C₄ alkyl radicals, C₁-C₄ monohydroxyalkylradicals and C₂-C₄ polyhydroxyalkyl radicals; (b) 5- and 6-memberednitrogenous heterocyclic groups optionally containing other heteroatomsor carbonyl groups and optionally substituted with at least one radicalchosen from C₁-C₄ alkyl radicals, an amino radical, a phenyl radical,and (ii) at least one thickening polymer chosen from polymerscomprising: (ii)₁—nonionic guar gums; (ii)₂—biopolysaccharide gums ofmicrobial origin; (ii)₃—gums derived from plant exudates; (ii)₄—pectins;(ii)₅—alginates; (ii)₆—starches; and (ii)₇—carboxyalkylcelluloses. 37.The process according to claim 36, wherein said process furthercomprises rinsing said fibers, then drying said fibers.
 38. The processaccording to claim 36, wherein said process further comprises washingsaid fibers with shampoo, a second rinsing of said fibers and drying ofsaid fibers.
 39. A process for dyeing keratin fibers, comprisingseparately storing a first composition, separately storing a secondcomposition, thereafter mixing said first and second compositions,applying said mixture to said fibers, and developing for a period oftime sufficient to achieve the desired coloration, wherein said firstcomposition comprises at least one cationic direct, at least onethickening polymer and at least one oxidation base: (i) wherein said atleast one cationic dye is chosen from compounds of formula (I) below:A—N═N—B  (I)  in which: the symbol A represents a group chosen from thestructures A₁ to A₃ below:

 in which structures A₁ to A₃, R₁ is chosen from C₁-C₄ alkyl radicals, aphenyl radical which can be substituted with a C₁-C₄ alkyl radical or ahalogen atom chosen from chlorine, bromine, iodine and fluorine; R₂ ischosen from C₁-C₄ alkyl radicals and a phenyl radical; R₃ and R₄, whichmay be identical or different, are chosen from C₁-C₄ alkyl radicals, aphenyl radical or, together form, in A₁, a benzene ring substituted withat least one radical chosen from C₁-C₄ alkyl radicals, C₁-C₄ alkoxyradicals and NO₂ radicals or, together form, in A₂, a benzene ringoptionally substituted with at least one radical chosen from C₁-C₄ alkylradicals, C₁-C₄ alkoxy radicals and NO₂ radicals; R₃ can be furtherchosen from a hydrogen atom; Z is chosen from an oxygen atom, a sulphuratom and —NR₂ radicals; M is chosen from a —CH radical, —C(C₁-C₄ alkyl)radicals and —N⁺ R₅(X⁻)_(r) radicals; K is chosen from a —CH radical,—C(C₁-C₄ alkyl) radicals and —N⁺ R₅(X⁻)_(r) radicals; P is chosen from a—CH radical, —C(C₁-C₄ alkyl) radicals and —N⁺ R₅(X⁻)_(r) radicals;wherein r denotes zero or 1; wherein R₅ is chosen from an O⁻ anion,C₁-C₄ alkoxy radicals and C₁-C₄ alkyl radicals; R₆ and R₇, which may beidentical or different, are chosen from a hydrogen atom, halogen atomschosen from chlorine, bromine, iodine and fluorine, C₁-C₄ alkylradicals, C₁-C₄ alkoxy radicals, and —NO₂ radicals; X⁻ is chosen fromanions;  with the proviso that, wherein if R₄ is a C₁-C₄ alkyl radicaland Z denotes a sulphur atom, R₃ is not a hydrogen atom; wherein if R₅is O⁻, then r is zero; wherein if K or P or M is C₁-C₄ —N⁺ -alkyl X⁻,either R₆ or R₇ is not a hydrogen atom; wherein if K is —N⁺ R₅(X⁻)_(r),M and P are the same and are chosen from a —CH radical and —C(C₁-C₄alkyl) radicals; wherein if M is —N⁺ R₅(X⁻)_(r), K and P are the sameand are chosen from a —CH radical and —C(C₁-C₄ alkyl) radicals; if Pdenotes —N⁺ R₅(X⁻)_(r), K and M are the same and are chosen from a —CHradical and —C(C₁-C₄ alkyl) radicals; if Z is —NR₂ with R₂ being aradical chosen from C₁-C₄ alkyl radicals, at least one of the radicalsR₁, R₃ or R₄ of A₂ is not chosen from C₁-C₄ alkyl radicals; the symbol Bis chosen from: (a) a group of structure B₁ below:

 in which structure B₁, R₈ is chosen from a hydrogen atom, a halogenatom chosen from chlorine, bromine, iodine and fluorine, C₁-C₄ alkylradicals, C₁-C₄ alkoxy radicals, a radical —OH, a radical —NO₂, —NHR₁₁radicals, —NR₁₂R₁₃ radicals, —NHCO (C₁-C₄) alkyl radicals, or forms withR₉ a 5- or 6-membered ring which may or may not contain at least onehetero atom chosen from nitrogen, oxygen and sulphur; R₉ is chosen froma hydrogen atom, a halogen atom chosen from chlorine, bromine, iodineand fluorine, C₁-C₄ alkyl radicals, C₁-C₄ alkoxy radicals, or forms,with R₁₀ or R₁₁, a 5- or 6-membered ring which may or may not contain atleast one hetero atom chosen from nitrogen, oxygen and sulphur; R₁₀ ischosen from a hydrogen atom, an —OH radical, —NHR₁₁ radicals and—NR₁₂R₁₃ radicals; R₁₁ is chosen from a hydrogen atom, C₁-C₄ alkylradicals, C₁-C₄ monohydroxyalkyl radicals, C₂-C₄ polyhydroxyalkylradicals and a phenyl radical; R₁₂ and R₁₃, which may be identical ordifferent, is chosen from C₁-C₄ alkyl radicals, C₁-C₄ monohydroxyalkylradicals and C₂-C₄ polyhydroxyalkyl radicals; (b) 5- and 6-memberednitrogenous heterocyclic groups optionally containing other heteroatomsor carbonyl groups and optionally substituted with at least one radicalchosen from C₁-C₄ alkyl radicals, an amino radical, a phenyl radical,and wherein said at least one thickening polymer is chosen from polymerscomprising: (ii)₁—nonionic guar gums; (ii)₂—biopolysaccharide gums ofmicrobial origin; (ii)₃—gums derived from plant exudates; (ii)₄—pectins;(ii)₅—alginates; (ii)₆—starches; and (ii)₇—carboxyalkylcelluloses;wherein said second composition comprises at least one oxidizing agent.40. A process for dyeing keratin fibers, comprising separately storing afirst composition, separately storing a second composition, thereaftermixing said first and second compositions, applying said mixture to saidfibers, and developing for a period of time sufficient to achieve thedesired coloration, wherein said first composition comprises at leastone oxidation base, and at least one cationic direct dye: (i) whereinsaid at least one cationic dye is chosen from compounds of formula (I)below: A—N═N—B  (I)  in which: the symbol A represents a group chosenfrom the structures A₁ to A₃ below:

 in which structures A₁ to A₃, R₁ is chosen from C₁-C₄ alkyl radicals, aphenyl radical which can be substituted with a C₁-C₄ alkyl radical or ahalogen atom chosen from chlorine, bromine, iodine and fluorine; R₂ ischosen from C₁-C₄ alkyl radicals and a phenyl radical; R₃ and R₄, whichmay be identical or different, are chosen from C₁-C₄ alkyl radicals, aphenyl radical or, together form, in A₁, a benzene ring substituted withat least one radical chosen from C₁-C₄ alkyl radicals, C₁-C₄ alkoxyradicals and NO₂ radicals or, together form, in A₂, a benzene ringoptionally substituted with at least one radical chosen from C₁-C₄ alkylradicals, C₁-C₄ alkoxy radicals and NO₂ radicals; R₃ can be furtherchosen from a hydrogen atom; Z is chosen from an oxygen atom, a sulphuratom and —NR₂ radicals; M is chosen from a —CH radical, —C(C₁-C₄ alkyl)radicals and —N⁺ R₅(X⁻)_(r) radicals; K is chosen from a —CH radical,—C(C₁-C₄ alkyl) radicals and —N⁺ R₅(X⁻)_(r) radicals; P is chosen from a—CH radical, —C(C₁-C₄ alkyl) radicals and —N⁺ R₅(X⁻)_(r) radicals;wherein r denotes zero or 1; wherein R₅ is chosen from an O⁻ anion,C₁-C₄ alkoxy radicals and C₁-C₄ alkyl radicals; R₆ and R₇, which may beidentical or different, are chosen from a hydrogen atom, halogen atomschosen from chlorine, bromine, iodine and fluorine, C₁-C₄ alkylradicals, C₁-C₄ alkoxy radicals, and —NO₂ radicals; X⁻ is chosen fromanions;  with the proviso that, wherein if R₄ is a C₁-C₄ alkyl radicaland Z denotes a sulphur atom, R₃ is not a hydrogen atom; wherein if R₅isO⁻, then r is zero; wherein if K or P or M is C₁-C₄ —N⁺ -alkyl X⁻,either R₆ or R₇ is not a hydrogen atom; wherein if K is —N⁺ R₅(X⁻)_(r),M and P are the same and are chosen from a —CH radical and —C(C₁-C₄alkyl) radicals; wherein if M is —N⁺ R₅(X⁻)_(r), K and P are the sameand are chosen from a —CH radical and —C(C₁-C₄ alkyl) radicals; if Pdenotes —N⁺ R₅(X⁻)_(r), K and M are the same and are chosen from a—CHradical and —C(C₁-C₄ alkyl) radicals; if Z is —NR₂ with R₂ being aradical chosen from C₁-C₄ alkyl radicals, at least one of the radicalsR₁, R₃ or R₄ of A₂ is not chosen from C₁-C₄ alkyl radicals; the symbol Bis chosen from: (a) a group of structure B₁ below:

 in which structure B₁, R₈ is chosen from a hydrogen atom, a halogenatom chosen from chlorine, bromine, iodine and fluorine, C₁-C₄ alkylradicals, C₁-C₄ alkoxy radicals, a radical —OH, a radical —NO₂, —NHR₁₁radicals, —NR₁₂R₁₃ radicals, —NHCO (C₁-C₄) alkyl radicals, or forms withR₉ a 5- or 6-membered ring which may or may not contain at least onehetero atom chosen from nitrogen, oxygen and sulphur; R₉ is chosen froma hydrogen atom, a halogen atom chosen from chlorine, bromine, iodineand fluorine, C₁-C₄ alkyl radicals, C₁-C₄ alkoxy radicals, or forms,with R₁₀ or R₁₁, a 5- or 6-membered ring which may or may not contain atleast one hetero atom chosen from nitrogen, oxygen and sulphur; R₁₀ ischosen from a hydrogen atom, an —OH radical, —NHR₁₁ radicals and—NR₁₂R₁₃ radicals; R₁₁ is chosen from a hydrogen atom, C₁-C₄ alkylradicals, C₁-C₄ monohydroxyalkyl radicals, C₂-C₄ polyhydroxyalkylradicals and a phenyl radical; R₁₂ and R₁₃, which may be identical ordifferent, is chosen from C₁-C₄ alkyl radicals, C₁-C₄ monohydroxyalkylradicals and C₂-C₄ polyhydroxyalkyl radicals; (b) 5- and 6-memberednitrogenous heterocyclic groups optionally containing other heteroatomsor carbonyl groups and optionally substituted with at least one radicalchosen from C₁-C₄ alkyl radicals, an amino radical, a phenyl radical,and wherein said second composition comprises at least one oxidizingagent and at least one thickening polymer, wherein said at least onethickening polymer is chosen from polymers comprising: (ii)₁—nonionicguar gums; (ii)₂—biopolysaccharide gums of microbial origin; (ii)₃—gumsderived from plant exudates; (ii)₄—pectins; (ii)₅—alginates;(ii)₆—starches; and (ii)₇—carboxyalkylcelluloses.
 41. A process fordyeing keratin fibers, comprising separately storing a firstcomposition, separately storing a second composition, thereafter mixingsaid first and second compositions, applying said mixture to saidfibers, and developing for a period of time sufficient to achieve thedesired coloration, wherein said first composition comprises at leastone cationic direct dye and at least one thickening polymer: (i) whereinsaid at least one cationic dye is chosen from compounds of formula (I)below: A—N═N—B  (I)  in which: the symbol A represents a group chosenfrom the structures A₁ to A₃ below:

 in which structures A₁ to A₃, R₁ is chosen from C₁-C₄ alkyl radicals, aphenyl radical which can be substituted with a C₁-C₄ alkyl radical or ahalogen atom chosen from chlorine, bromine, iodine and fluorine; R₂ ischosen from C₁-C₄ alkyl radicals and a phenyl radical; R₃ and R₄, whichmay be identical or different, are chosen from C₁-C₄ alkyl radicals, aphenyl radical or, together form, in A₁, a benzene ring substituted withat least one radical chosen from C₁-C₄ alkyl radicals, C₁-C₄ alkoxyradicals and NO₂ radicals or, together form, in A₂, a benzene ringoptionally substituted with at least one radical chosen from C₁-C₄ alkylradicals, C₁-C₄ alkoxy radicals and NO₂ radicals; R₃ can be furtherchosen from a hydrogen atom; Z is chosen from an oxygen atom, a sulphuratom and —NR₂ radicals; M is chosen from a —CH radical, —C(C₁-C₄ alkyl)radicals and —N⁺ R₅(X⁻)_(r) radicals; K is chosen from a —CH radical,—C(C₁-C₄ alkyl) radicals and —N⁺ R₅(X⁻)_(r) radicals; P is chosen from a—CH radical, —C(C₁-C₄ alkyl) radicals and —N⁺ R₅(X⁻)_(r) radicals;wherein r denotes zero or 1; wherein R₅ is chosen from an O⁻ anion,C₁-C₄ alkoxy radicals and C₁-C₄ alkyl radicals; R₆ and R₇, which may beidentical or different, are chosen from a hydrogen atom, halogen atomschosen from chlorine, bromine, iodine and fluorine, C₁-C₄ alkylradicals, C₁-C₄ alkoxy radicals, and —NO₂ radicals; X⁻ is chosen fromanions;  with the proviso that, wherein if R₄ is a C₁-C₄ alkyl radicaland Z denotes a sulphur atom, R₃ is not a hydrogen atom; wherein if R₅is O⁻, then r is zero; wherein if K or P or M is C₁-C₄ —N⁺ -alkyl X⁻,either R₆ or R₇ is not a hydrogen atom; wherein if K is —N⁺ R₅(X⁻)_(r),M and P are the same and are chosen from a —CH radical and —C(C₁-C₄alkyl) radicals; wherein if M is —N⁺ R₅(X⁻)_(r), K and P are the sameand are chosen from a —CH radical and —C(C₁-C₄ alkyl) radicals; if Pdenotes —N⁺ R₅(X⁻)_(r), K and M are the same and are chosen from a —CHradical and —C(C₁-C₄ alkyl) radicals; if Z is —NR₂ with R₂ being aradical chosen from C₁-C₄ alkyl radicals, at least one of the radicalsR₁, R₃ or R₄ of A₂ is not chosen from C₁-C₄ alkyl radicals; the symbol Bis chosen from: (a) a group of structure B₁ below:

 in which structure B₁, R₈ is chosen from a hydrogen atom, a halogenatom chosen from chlorine, bromine, iodine and fluorine, C₁-C₄ alkylradicals, C₁-C₄ alkoxy radicals, a radical —OH, a radical —NO₂, —NHR₁₁radicals, —NR₁₂R₁₃ radicals, —NHCO (C₁-C₄) alkyl radicals, or forms withR₉ a 5- or 6-membered ring which may or may not contain at least onehetero atom chosen from nitrogen, oxygen and sulphur; R₉ is chosen froma hydrogen atom, a halogen atom chosen from chlorine, bromine, iodineand fluorine, C₁-C₄ alkyl radicals, C₁-C₄ alkoxy radicals, or forms,with R₁₀ or R₁₁, a 5- or 6-membered ring which may or may not contain atleast one hetero atom chosen from nitrogen, oxygen and sulphur; R₁₀ ischosen from a hydrogen atom, an —OH radical, —NHR₁₁ radicals and—NR₁₂R₁₃ radicals; R₁₁ is chosen from a hydrogen atom, C₁-C₄ alkylradicals, C₁-C₄ monohydroxyalkyl radicals, C₂-C₄ polyhydroxyalkylradicals and a phenyl radical; R₁₂ and R₁₃, which may be identical ordifferent, is chosen from C₁-C₄ alkyl radicals, C₁-C₄ monohydroxyalkylradicals and C₂-C₄ polyhydroxyalkyl radicals; (b) 5- and 6-memberednitrogenous heterocyclic groups optionally containing other heteroatomsor carbonyl groups and optionally substituted with at least one radicalchosen from C₁-C₄ alkyl radicals, an amino radical, a phenyl radical,and and wherein said at least one thickening polymer is chosen frompolymers comprising: (ii)₁—nonionic guar gums; (ii)₂—biopolysaccharidegums of microbial origin; (ii)₃—gums derived from plant exudates;(ii)₄—pectins; (ii)₅—alginates; (ii)₆—starches; and(ii)₇—carboxyalkylcelluloses; wherein said second composition comprisesat least one oxidizing agent.
 42. A process for dyeing keratin fibers,comprising separately storing a first composition, separately storing asecond composition, thereafter mixing said first and secondcompositions, applying said mixture to said fibers, and developing for aperiod of time sufficient to achieve the desired coloration, whereinsaid first composition comprises at least one cationic direct dye: (i)wherein said at least one cationic dye is chosen from compounds offormula (I) below: A—N═N—B  (I)  in which: the symbol A represents agroup chosen from the structures A₁ to A₃ below:

 in which structures A₁ to A₃, R₁ is chosen from C₁-C₄ alkyl radicals, aphenyl radical which can be substituted with a C₁-C₄ alkyl radical or ahalogen atom chosen from chlorine, bromine, iodine and fluorine; R₂ ischosen from C₁-C₄ alkyl radicals and a phenyl radical; R₃ and R₄, whichmay be identical or different, are chosen from C₁-C₄ alkyl radicals, aphenyl radical or, together form, in A₁, a benzene ring substituted withat least one radical chosen from C₁-C₄ alkyl radicals, C₁-C₄ alkoxyradicals and NO₂ radicals or, together form, in A₂, a benzene ringoptionally substituted with at least one radical chosen from C₁-C₄ alkylradicals, C₁-C₄ alkoxy radicals and NO₂ radicals; R₃ can be furtherchosen from a hydrogen atom; Z is chosen from an oxygen atom, a sulphuratom and —NR₂ radicals; M is chosen from a —CH radical, —C(C₁-C₄ alkyl)radicals and —N⁺ R₅(X⁻)_(r) radicals; K is chosen from a —CH radical,—C(C₁-C₄ alkyl) radicals and —N⁺ R₅(X⁻)_(r) radicals; P is chosen from a—CH radical, —C(C₁-C₄ alkyl) radicals and —N⁺ R₅(X⁻)_(r) radicals;wherein r denotes zero or 1; wherein R₅ is chosen from an O⁻ anion,C₁-C₄ alkoxy radicals and C₁-C₄ alkyl radicals; R₆ and R₇, which may beidentical or different, are chosen from a hydrogen atom, halogen atomschosen from chlorine, bromine, iodine and fluorine, C₁-C₄ alkylradicals, C₁-C₄ alkoxy radicals, and —NO₂ radicals; X⁻ is chosen fromanions;  with the proviso that, wherein if R₄ is a C₁-C₄ alkyl radicaland Z denotes a sulphur atom, R₃ is not a hydrogen atom; wherein if R₅is O⁻, then r is zero; wherein if K or P or M is C₁-C₄ —N⁺ -alkyl X⁻,either R₆ or R₇ is not a hydrogen atom; wherein if K is —N⁺ R₅(X⁻)_(r),M and P are the same and are chosen from a —CH radical and —C(C₁-C₄alkyl) radicals; wherein if M is —N⁺ R₅(X⁻)_(r), K and P are the sameand are chosen from a —CH radical and —C(C₁-C₄ alkyl) radicals; if Pdenotes —N⁺ R₅(X⁻)_(r), K and M are the same and are chosen from a —CHradical and —C(C₁-C₄ alkyl) radicals; if Z is —NR₂ with R₂ being aradical chosen from C₁-C₄ alkyl radicals, at least one of the radicalsR₁, R₃ or R₄ of A₂ is not chosen from C₁-C₄ alkyl radicals; the symbol Bis chosen from: (a) a group of structure B₁ below:

 in which structure B₁, R₈ is chosen from a hydrogen atom, a halogenatom chosen from chlorine, bromine, iodine and fluorine, C₁-C₄ alkylradicals, C₁-C₄ alkoxy radicals, a radical —OH, a radical —NO₂, —NHR₁₁radicals, —NR₁₂R₁₃ radicals, —NHCO (C₁-C₄) alkyl radicals, or forms withR₉ a 5- or 6-membered ring which may or may not contain at least onehetero atom chosen from nitrogen, oxygen and sulphur; R₉ is chosen froma hydrogen atom, a halogen atom chosen from chlorine, bromine, iodineand fluorine, C₁-C₄ alkyl radicals, C₁-C₄ alkoxy radicals, or forms,with R₁₀ or R₁₁, a 5- or 6-membered ring which may or may not contain atleast one hetero atom chosen from nitrogen, oxygen and sulphur; R₁₀ ischosen from a hydrogen atom, an —OH radical, —NHR₁₁ radicals and—NR₁₂R₁₃ radicals; R₁₁ is chosen from a hydrogen atom, C₁-C₄ alkylradicals, C₁-C₄ monohydroxyalkyl radicals, C₂-C₄ polyhydroxyalkylradicals and a phenyl radical; R₁₂ and R₁₃, which may be identical ordifferent, is chosen from C₁-C₄ alkyl radicals, C₁-C₄ monohydroxyalkylradicals and C₂-C₄ polyhydroxyalkyl radicals; (b) 5- and 6-memberednitrogenous heterocyclic groups optionally containing other heteroatomsor carbonyl groups and optionally substituted with at least one radicalchosen from C₁-C₄ alkyl radicals, an amino radical, a phenyl radical,and wherein said second composition comprises at least one oxidizingagent and at least one thickening polymer, wherein said at least onethickening polymer is chosen from polymers comprising: (ii)₁—nonionicguar gums; (ii)₂—biopolysaccharide gums of microbial origin; (ii)₃—gumsderived from plant exudates; (ii)₄—pectins; (ii)₅—alginates;(ii)₆—starches; and (ii)₇—carboxyalkylcelluloses.
 43. Amulti-compartment dyeing kit, comprising at least two separatecompartments, wherein a first compartment contains a first compositionand a second compartment contains a second composition, wherein saidfirst composition comprises at least one cationic direct dye, at leastone thickening polymer and at least one oxidation base, (i) wherein saidat least one cationic dye is chosen from compounds of formula (I) below:A—N═N—B  (I)  in which: the symbol A represents a group chosen from thestructures A₁ to A₃ below:

 in which structures A₁ to A₃, R₁ is chosen from C₁-C₄ alkyl radicals, aphenyl radical which can be substituted with a C₁-C₄ alkyl radical or ahalogen atom chosen from chlorine, bromine, iodine and fluorine; R₂ ischosen from C₁-C₄ alkyl radicals and a phenyl radical; R₃ and R₄, whichmay be identical or different, are chosen from C₁-C₄ alkyl radicals, aphenyl radical or, together form, in A₁, a benzene ring substituted withat least one radical chosen from C₁-C₄ alkyl radicals, C₁-C₄ alkoxyradicals and NO₂ radicals or, together form, in A₂, a benzene ringoptionally substituted with at least one radical chosen from C₁-C₄ alkylradicals, C₁-C₄ alkoxy radicals and NO₂ radicals; R₃ can be furtherchosen from a hydrogen atom; Z is chosen from an oxygen atom, a sulphuratom and —NR₂ radicals; M is chosen from a —CH radical, —C(C₁-C₄ alkyl)radicals and —N⁺ R₅(X⁻)_(r) radicals; K is chosen from a —CH radical,—C(C₁-C₄ alkyl) radicals and —N⁺ R₅(X⁻)_(r) radicals; P is chosen from a—CH radical, —C(C₁-C₄ alkyl) radicals and —N⁺ R₅(X⁻)_(r) radicals;wherein r denotes zero or 1; wherein R₅ is chosen from an O⁻ anion,C₁-C₄ alkoxy radicals and C₁-C₄ alkyl radicals; R₆ and R₇, which may beidentical or different, are chosen from a hydrogen atom, halogen atomschosen from chlorine, bromine, iodine and fluorine, C₁-C₄ alkylradicals, C₁-C₄ alkoxy radicals, and —NO₂ radicals; X⁻ is chosen fromanions;  with the proviso that, wherein if R₄ is a C₁-C₄ alkyl radicaland Z denotes a sulphur atom, R₃ is not a hydrogen atom; wherein if R₅is O⁻, then r is zero; wherein if K or P or M is C₁-C₄ —N⁺ -alkyl X⁻,either R₆ or R₇ is not a hydrogen atom; wherein if K is —N⁺ R₅(X⁻)_(r),M and P are the same and are chosen from a —CH radical and —C(C₁-C₄alkyl) radicals; wherein if M is —N⁺ R₅(X⁻)_(r), K and P are the sameand are chosen from a —CH radical and —C(C₁-C₄ alkyl) radicals; if Pdenotes —N⁺ R₅(X⁻)_(r), K and M are the same and are chosen from a—CHradical and —C(C₁-C₄ alkyl) radicals; if Z is —NR₂ with R₂ being aradical chosen from C₁-C₄ alkyl radicals, at least one of the radicalsR₁, R₃ or R₄ of A₂ is not chosen from C₁-C₄ alkyl radicals; the symbol Bis chosen from: (a) a group of structure B₁ below:

 in which structure B₁, R₈ is chosen from a hydrogen atom, a halogenatom chosen from chlorine, bromine, iodine and fluorine, C₁-C₄ alkylradicals, C₁-C₄ alkoxy radicals, a radical —OH, a radical —NO₂, —NHR₁₁radicals, —NR₁₂R₁₃ radicals, —NHCO (C₁-C₄) alkyl radicals, or forms withR₉ a 5- or 6-membered ring which may or may not contain at least onehetero atom chosen from nitrogen, oxygen and sulphur; R₉ is chosen froma hydrogen atom, a halogen atom chosen from chlorine, bromine, iodineand fluorine, C₁-C₄ alkyl radicals, C₁-C₄ alkoxy radicals, or forms,with R₁₀ or R₁₁, a 5- or 6-membered ring which may or may not contain atleast one hetero atom chosen from nitrogen, oxygen and sulphur; R₁₀ ischosen from a hydrogen atom, an —OH radical, —NHR₁₁ radicals and—NR₁₂R₁₃ radicals; R₁₁ is chosen from a hydrogen atom, C₁-C₄ alkylradicals, C₁-C₄ monohydroxyalkyl radicals, C₂-C₄ polyhydroxyalkylradicals and a phenyl radical; R₁₂ and R₁₃, which may be identical ordifferent, is chosen from C₁-C₄ alkyl radicals, C₁-C₄ monohydroxyalkylradicals and C₂-C₄ polyhydroxyalkyl radicals; (b) 5- and 6-memberednitrogenous heterocyclic groups optionally containing other heteroatomsor carbonyl groups and optionally substituted with at least one radicalchosen from C₁-C₄ alkyl radicals, an amino radical, a phenyl radical,wherein said at least one thickening polymer is chosen from polymerscomprising: (ii)₁—nonionic guar gums; (ii)₂—biopolysaccharide gums ofmicrobial origin; (ii)₃—gums derived from plant exudates; (ii)₄—pectins;(ii)₅—alginates; (ii)₆—starches; and (ii)₇—carboxyalkylcelluloses; andwherein said second composition comprises at least one oxidizing agent.44. A multi-compartment dyeing kit, comprising at least two separatecompartments, wherein a first compartment contains a first compositionand a second compartment contains a second composition, wherein saidfirst composition comprises at least one oxidation base and at least onecationic direct dye: (i) wherein said at least one cationic dye ischosen from compounds of formula (I) below: A—N═N—B  (I)  in which: thesymbol A represents a group chosen from the structures A₁ to A₃ below:

 in which structures A₁ to A₃, R₁ is chosen from C₁-C₄ alkyl radicals, aphenyl radical which can be substituted with a C₁-C₄ alkyl radical or ahalogen atom chosen from chlorine, bromine, iodine and fluorine; R₂ ischosen from C₁-C₄ alkyl radicals and a phenyl radical; R₃ and R₄, whichmay be identical or different, are chosen from C₁-C₄ alkyl radicals, aphenyl radical or, together form, in A₁, a benzene ring substituted withat least one radical chosen from C₁-C₄ alkyl radicals, C₁-C₄ alkoxyradicals and NO₂ radicals or, together form, in A₂, a benzene ringoptionally substituted with at least one radical chosen from C₁-C₄ alkylradicals, C₁-C₄ alkoxy radicals and NO₂ radicals; R₃ can be furtherchosen from a hydrogen atom; Z is chosen from an oxygen atom, a sulphuratom and —NR₂ radicals; M is chosen from a —CH radical, —C(C₁-C₄ alkyl)radicals and —N⁺ R₅(X⁻)_(r) radicals; K is chosen from a —CH radical,—C(C₁-C₄ alkyl) radicals and —N⁺ R₅(X⁻)_(r) radicals; P is chosen from a—CH radical, —C(C₁-C₄ alkyl) radicals and —N⁺ R₅(X⁻)_(r) radicals;wherein r denotes zero or 1; wherein R₅ is chosen from an O⁻ anion,C₁-C₄ alkoxy radicals and C₁-C₄ alkyl radicals; R₆ and R₇, which may beidentical or different, are chosen from a hydrogen atom, halogen atomschosen from chlorine, bromine, iodine and fluorine, C₁-C₄ alkylradicals, C₁-C₄ alkoxy radicals, and —NO₂ radicals; X⁻ is chosen fromanions;  with the proviso that, wherein if R₄ is a C₁-C₄ alkyl radicaland Z denotes a sulphur atom, R₃ is not a hydrogen atom; wherein if R₅is O⁻, then r is zero; wherein if K or P or M is C₁-C₄ —N⁺ -alkyl X⁻,either R₆ or R₇ is not a hydrogen atom; wherein if K is —N⁺ R₅(X⁻)_(r),M and P are the same and are chosen from a —CH radical and —C(C₁-C₄alkyl) radicals; wherein if M is —N⁺ R₅(X⁻)_(r), K and P are the sameand are chosen from a —CH radical and —C(C₁-C₄ alkyl) radicals; if Pdenotes —N⁺ R₅(X⁻)_(r), K and M are the same and are chosen from a —CHradical and —C(C₁-C₄ alkyl) radicals; if Z is —NR₂ with R₂ being aradical chosen from C₁-C₄ alkyl radicals, at least one of the radicalsR₁, R₃ or R₄ of A₂ is not chosen from C₁-C₄ alkyl radicals; the symbol Bis chosen from: (a) a group of structure B₁ below:

 in which structure B₁, R₈ is chosen from a hydrogen atom, a halogenatom chosen from chlorine, bromine, iodine and fluorine, C₁-C₄ alkylradicals, C₁-C₄ alkoxy radicals, a radical —OH, a radical —NO₂, —NHR₁₁radicals, —NR₁₂R₁₃ radicals, —NHCO (C₁-C₄) alkyl radicals, or forms withR₉ a 5- or 6-membered ring which may or may not contain at least onehetero atom chosen from nitrogen, oxygen and sulphur; R₉ is chosen froma hydrogen atom, a halogen atom chosen from chlorine, bromine, iodineand fluorine, C₁-C₄ alkyl radicals, C₁-C₄ alkoxy radicals, or forms,with R₁₀ or R₁₁, a 5- or 6-membered ring which may or may not contain atleast one hetero atom chosen from nitrogen, oxygen and sulphur; R₁₀ ischosen from a hydrogen atom, an —OH radical, —NHR₁₁ radicals and—NR₁₂R₁₃ radicals; R₁₁ is chosen from a hydrogen atom, C₁-C₄ alkylradicals, C₁-C₄ monohydroxyalkyl radicals, C₂-C₄ polyhydroxyalkylradicals and a phenyl radical; R₁₂ and R₁₃, which may be identical ordifferent, is chosen from C₁-C₄ alkyl radicals, C₁-C₄ monohydroxyalkylradicals and C₂-C₄ polyhydroxyalkyl radicals; (b) 5- and 6-memberednitrogenous heterocyclic groups optionally containing other heteroatomsor carbonyl groups and optionally substituted with at least one radicalchosen from C₁-C₄ alkyl radicals, an amino radical, a phenyl radical,and and wherein said second composition comprises at least one oxidizingagent and at least one thickening polymer, wherein said at least onethickening polymer is chosen from polymers comprising: (ii)₁—nonionicguar gums; (ii)₂—biopolysaccharide gums of microbial origin; (ii)₃—gumsderived from plant exudates; (ii)₄ —pectins; (ii)₅—alginates;(ii)₆—starches; and (ii)₇—carboxyalkylcelluloses.
 45. Amulti-compartment dyeing kit, comprising at least two separatecompartments, wherein a first compartment contains a first compositionand a second compartment contains a second composition, wherein saidfirst composition comprises at least one thickening polymer and at leastone cationic direct dye: (i) wherein said at least one cationic dye ischosen from compounds of formula (I) below: A—N═N—B  (I)  in which: thesymbol A represents a group chosen from the structures A₁ to A₃ below:

 in which structures A₁ to A₃, R₁ is chosen from C₁-C₄ alkyl radicals, aphenyl radical which can be substituted with a C₁-C₄ alkyl radical or ahalogen atom chosen from chlorine, bromine, iodine and fluorine; R₂ ischosen from C₁-C₄ alkyl radicals and a phenyl radical; R₃ and R₄, whichmay be identical or different, are chosen from C₁-C₄ alkyl radicals, aphenyl radical or, together form, in A₁, a benzene ring substituted withat least one radical chosen from C₁-C₄ alkyl radicals, C₁-C₄ alkoxyradicals and NO₂ radicals or, together form, in A₂, a benzene ringoptionally substituted with at least one radical chosen from C₁-C₄ alkylradicals, C₁-C₄ alkoxy radicals and NO₂ radicals; R₃ can be furtherchosen from a hydrogen atom; Z is chosen from an oxygen atom, a sulphuratom and —NR₂ radicals; M is chosen from a —CH radical, —C(C₁-C₄ alkyl)radicals and —N⁺ R₅(X⁻)_(r) radicals; K is chosen from a —CH radical,—C(C₁-C₄ alkyl) radicals and —N⁺ R₅(X⁻)_(r) radicals; P is chosen from a—CH radical, —C(C₁-C₄ alkyl) radicals and —N⁺ R₅(X⁻)_(r) radicals;wherein r denotes zero or 1; wherein R₅ is chosen from an O⁻ anion,C₁-C₄ alkoxy radicals and C₁-C₄ alkyl radicals; R₆ and R₇, which may beidentical or different, are chosen from a hydrogen atom, halogen atomschosen from chlorine, bromine, iodine and fluorine, C₁-C₄ alkylradicals, C₁-C₄ alkoxy radicals, and —NO₂ radicals; X⁻ is chosen fromanions;  with the proviso that, wherein if R₄ is a C₁-C₄ alkyl radicaland Z denotes a sulphur atom, R₃ is not a hydrogen atom; wherein if R₅is O⁻, then r is zero; wherein if K or P or M is C₁-C₄ —N⁺ -alkyl X⁻,either R₆ or R₇ is not a hydrogen atom; wherein if K is —N⁺ R₅(X⁻)_(r),M and P are the same and are chosen from a —CH radical and —C(C₁-C₄alkyl) radicals; wherein if M is —N⁺ R₅(X⁻)_(r), K and P are the sameand are chosen from a —CH radical and —C(C₁-C₄ alkyl) radicals; if Pdenotes —N⁺ R₅(X⁻)_(r), K and M are the same and are chosen from a —CHradical and —C(C₁-C₄ alkyl) radicals; if Z is —NR₂ with R₂ being aradical chosen from C₁-C₄ alkyl radicals, at least one of the radicalsR₁, R₃ or R₄ of A₂ is not chosen from C₁-C₄ alkyl radicals; the symbol Bis chosen from: (a) a group of structure B₁ below:

 in which structure B₁, R₈ is chosen from a hydrogen atom, a halogenatom chosen from chlorine, bromine, iodine and fluorine, C₁-C₄ alkylradicals, C₁-C₄ alkoxy radicals, a radical —OH, a radical —NO₂, —NHR₁₁radicals, —NR₁₂R₁₃ radicals, —NHCO (C₁-C₄) alkyl radicals, or forms withR₉ a 5- or 6-membered ring which may or may not contain at least onehetero atom chosen from nitrogen, oxygen and sulphur; R₉ is chosen froma hydrogen atom, a halogen atom chosen from chlorine, bromine, iodineand fluorine, C₁-C₄ alkyl radicals, C₁-C₄ alkoxy radicals, or forms,with R₁₀ or R₁₁, a 5- or 6-membered ring which may or may not contain atleast one hetero atom chosen from nitrogen, oxygen and sulphur; R₁₀ ischosen from a hydrogen atom, an —OH radical, —NHR₁₁ radicals and—NR₁₂R₁₃ radicals; R₁₁ is chosen from a hydrogen atom, C₁-C₄ alkylradicals, C₁-C₄ monohydroxyalkyl radicals, C₂-C₄ polyhydroxyalkylradicals and a phenyl radical; R₁₂ and R₁₃, which may be identical ordifferent, is chosen from C₁-C₄ alkyl radicals, C₁-C₄ monohydroxyalkylradicals and C₂-C₄ polyhydroxyalkyl radicals; (b) 5- and 6-memberednitrogenous heterocyclic groups optionally containing other heteroatomsor carbonyl groups and optionally substituted with at least one radicalchosen from C₁-C₄ alkyl radicals, an amino radical, a phenyl radical,and wherein said at least one thickening polymer is chosen from polymerscomprising: (ii)₁—nonionic guar gums; (ii)₂—biopolysaccharide gums ofmicrobial origin; (ii)₃—gums derived from plant exudates; (ii)₄—pectins; (ii)₅—alginates; (ii)₆—starches; and(ii)₇—carboxyalkylcelluloses; and wherein said second compositioncomprises at least one oxidizing agent.
 46. A multi-compartment dyeingkit, comprising at least two separate compartments, wherein a firstcompartment contains a first composition and a second compartmentcontains a second composition, wherein said first composition comprisesat least one cationic direct dye: (i) wherein said at least one cationicdye is chosen from compounds of formula (I) below: A—N═N—B  (I)  inwhich: the symbol A represents a group chosen from the structures A₁ toA₃ below:

 in which structures A₁ to A₃, R₁ is chosen from C₁-C₄ alkyl radicals, aphenyl radical which can be substituted with a C₁-C₄ alkyl radical or ahalogen atom chosen from chlorine, bromine, iodine and fluorine; R₂ ischosen from C₁-C₄ alkyl radicals and a phenyl radical; R₃ and R₄, whichmay be identical or different, are chosen from C₁-C₄ alkyl radicals, aphenyl radical or, together form, in A₁, a benzene ring substituted withat least one radical chosen from C₁-C₄ alkyl radicals, C₁-C₄ alkoxyradicals and NO₂ radicals or, together form, in A₂, a benzene ringoptionally substituted with at least one radical chosen from C₁-C₄ alkylradicals, C₁-C₄ alkoxy radicals and NO₂ radicals; R₃ can be furtherchosen from a hydrogen atom; Z is chosen from an oxygen atom, a sulphuratom and —NR₂ radicals; M is chosen from a —CH radical, —C(C₁-C₄ alkyl)radicals and —N⁺ R₅(X⁻)_(r) radicals; K is chosen from a —CH radical,—C(C₁-C₄ alkyl) radicals and —N⁺ R₅(X⁻)_(r) radicals; P is chosen from a—CH radical, —C(C₁-C₄ alkyl) radicals and —N⁺ R₅(X⁻)_(r) radicals;wherein r denotes zero or 1; wherein R₅ is chosen from an O⁻ anion,C₁-C₄ alkoxy radicals and C₁-C₄ alkyl radicals; R₆ and R₇, which may beidentical or different, are chosen from a hydrogen atom, halogen atomschosen from chlorine, bromine, iodine and fluorine, C₁-C₄ alkylradicals, C₁-C₄ alkoxy radicals, and —NO₂ radicals; X⁻ is chosen fromanions;  with the proviso that, wherein if R₄ is a C₁-C₄ alkyl radicaland Z denotes a sulphur atom, R₃ is not a hydrogen atom; wherein if R₅is O⁻, then r is zero; wherein if K or P or M is C₁-C₄ —N⁺ -alkyl X⁻,either R₆ or R₇ is not a hydrogen atom; wherein if K is —N⁺ R₅(X⁻)_(r),M and P are the same and are chosen from a —CH radical and —C(C₁-C₄alkyl) radicals; wherein if M is —N⁺ R₅(X⁻)_(r), K and P are the sameand are chosen from a —CH radical and —C(C₁-C₄ alkyl) radicals; if Pdenotes —N⁺ R₅(X⁻)_(r), K and M are the same and are chosen from a —CHradical and —C(C₁-C₄ alkyl) radicals; if Z is —NR₂ with R₂ being aradical chosen from C₁-C₄ alkyl radicals, at least one of the radicalsR₁, R₃ or R₄ of A₂ is not chosen from C₁-C₄ alkyl radicals; the symbol Bis chosen from: (a) a group of structure B₁ below:

 in which structure B₁, R₈ is chosen from a hydrogen atom, a halogenatom chosen from chlorine, bromine, iodine and fluorine, C₁-C₄ alkylradicals, C₁-C₄ alkoxy radicals, a radical —OH, a radical —NO₂, —NHR₁₁radicals, —NR₁₂R₁₃ radicals, —NHCO (C₁-C₄) alkyl radicals, or forms withR₉ a 5- or 6-membered ring which may or may not contain at least onehetero atom chosen from nitrogen, oxygen and sulphur; R₉ is chosen froma hydrogen atom, a halogen atom chosen from chlorine, bromine, iodineand fluorine, C₁-C₄ alkyl radicals, C₁-C₄ alkoxy radicals, or forms,with R₁₀ or R₁₁, a 5- or 6-membered ring which may or may not contain atleast one hetero atom chosen from nitrogen, oxygen and sulphur; R₁₀ ischosen from a hydrogen atom, an —OH radical, —NHR₁₁ radicals and—NR₁₂R₁₃ radicals; R₁₁ is chosen from a hydrogen atom, C₁-C₄ alkylradicals, C₁-C₄ monohydroxyalkyl radicals, C₂-C₄ polyhydroxyalkylradicals and a phenyl radical; R₁₂ and R₁₃, which may be identical ordifferent, is chosen from C₁-C₄ alkyl radicals, C₁-C₄ monohydroxyalkylradicals and C₂-C₄ polyhydroxyalkyl radicals; (b) 5- and 6-memberednitrogenous heterocyclic groups optionally containing other heteroatomsor carbonyl groups and optionally substituted with at least one radicalchosen from C₁-C₄ alkyl radicals, an amino radical, a phenyl radical,and wherein said second composition comprises at least one oxidizingagent and at least one thickening polymer, wherein said at least onethickening polymer is chosen from polymers comprising: (ii)₁—nonionicguar gums; (ii)₂—biopolysaccharide gums of microbial origin; (ii)₃—gumsderived from plant exudates; (ii)₄ —pectins; (ii)₅—alginates;(ii)₆—starches; and (ii)₇—carboxyalkylcelluloses.